I really need to get pics of my setup on here
Do you have a local CB shop?
You can get a stake hole mount and can mount your antenna off the side your bedrail just behind the cab of the truck
Here is link/pic of it I found online
http://www.www.premiere-electronics....re/ss194a.html
I had to mount the bracket little off the side of the stake hole, the antenna would hit the bed when mounted in stake hole so I just moved it off to the side a little more, drilled 4 holes and installed as normal. I have mine on passenger side of bed, 1st stake hole behind cab. I have a 3' wilson fiberglass antenna on a spring and clear an 8' garage door. Also this does not affect my vinyl cover that I have installed on bed
Also, bumper mount is worst place to mount an antenna, best place is mag mount on roof-but out of question-next best is bed rail behind cab with at least 50% of antenna above roof line. Just FYI